#!/usr/bin/env python
# -*- coding: latin-1 -*-
import os, sys
from string import *

def DecodCesar(MaStringEncodee, decalage):
	return translate(MaStringEncodee, maketrans( letters , letters[decalage:]+letters[:decalage] ))

if (len(sys.argv) > 1 ):
	print DecodCesar(sys.argv[1],-5)
else:
	print DecodCesar("Hello world",5)
